fix: clarify invalid selectors and dedupe diagnostics

crates/bsk-cli/src/cli/error.rs

@@ -497,4 +497,21 @@ mod tests {
                 .contains("CSS selector")
         );
     }
+
+    #[test]
+    fn invalid_selector_explains_css_contract_in_json() {
+        let cli = CliError::from_rpc(RpcError {
+            code: ErrorCode::InvalidParams,
+            message: "selector is not valid CSS: text=submit".into(),
+            data: Some(serde_json::json!({ "reason": "invalid_selector" })),
+        });
+        let exit = cli.exit_code();
+        let hint = hint_for(&cli, render_info_for(&cli).as_ref());
+        let json = json_error_string(&cli, exit, hint);
+        let parsed: serde_json::Value = serde_json::from_str(&json).unwrap();
+        let hint = parsed.get("hint").and_then(|v| v.as_str()).unwrap();
+        assert!(hint.contains("CSS selector"));
+        assert!(hint.contains("text="));
+        assert!(hint.contains("@eN"));
+    }
 }

crates/bsk-cli/src/cli/render_error.rs

@@ -41,6 +41,7 @@ pub mod reason {
     pub const AGENT_WINDOW_SCOPE: &str = "agent_window_scope";
     pub const ELEMENT_NOT_VISIBLE: &str = "element_not_visible";
     pub const REF_NOT_FOUND: &str = "ref_not_found";
+    pub const INVALID_SELECTOR: &str = "invalid_selector";
     pub const SELECTOR_NOT_FOUND: &str = "selector_not_found";
     pub const TARGET_NOT_FILLABLE: &str = "target_not_fillable";
     pub const TARGET_NOT_SELECT: &str = "target_not_select";
@@ -221,6 +222,13 @@ pub fn info_for_error(code: ErrorCode, data: Option<&serde_json::Value>) -> Rend
             hint: Some("verify the CSS selector or wait for the element to appear before retrying"),
             exit_code: base.exit_code,
         },
+        (ErrorCode::InvalidParams, reason::INVALID_SELECTOR) => RenderInfo {
+            summary: "selector is not valid CSS",
+            hint: Some(
+                "use a standard CSS selector or a fresh @eN ref; Playwright text= selectors and XPath are not supported",
+            ),
+            exit_code: base.exit_code,
+        },
         (ErrorCode::InvalidParams, reason::TARGET_NOT_FILLABLE) => RenderInfo {
             summary: "target element is not fillable",
             hint: Some(

crates/bsk-cli/src/daemon/start.rs

@@ -40,7 +40,7 @@ pub(crate) const DAEMONIZED_ENV: &str = "BSK_DAEMONIZED";
 /// daemon lock, IPC socket, and WS port — before taking over.
 pub(crate) const DAEMON_REPLACEMENT_WAIT_ENV: &str = "BSK_DAEMON_REPLACES_PID";
 
-const LUMI_DIAGNOSTIC_BUILD: &str = "lumi-session-loss-v1";
+const LUMI_DIAGNOSTIC_BUILD: &str = "lumi-session-loss-v2";
 
 /// Concrete daemon configuration resolved from CLI flags / defaults.
 #[derive(Debug, Clone)]